Torque and combined load fixture and test method

Abstract

A method and apparatus for testing a specimen with pressure, applying a torque using one or more plates coupled to the test specimen, applying a bending moment, and/or applying an axial load, either separately or simultaneously, with or without rotating the specimen, and without the applied forces interfering with each other.

What is claimed is: 
     
       1. An apparatus for testing a specimen comprising:
 a tubular housing with a first end and a second end; 
 a first end assembly, coupled to a first end of a tubular, further comprising a first cylindrical body having a plurality of recessed, axially oriented cylindrical half grooves located radially outward; 
 a second cylindrical body having a plurality of evenly spaced, recessed, axially oriented cylindrical half grooves located radially inward, wherein the first cylindrical body is disposed within, and axially aligned with, the second cylindrical body with the grooves of both cylindrical bodies align with, and complement each other to form a first plurality of cylindrical cavities within the assembly; 
 a sphere located within each of the first plurality of cylindrical cavities, forming a plurality of spheres, where the sphere can move during axial movement of the first cylindrical body relative to the second cylindrical body, and transmits a torque about the axis resulting from rotational movement of the first cylindrical body relative to the second cylindrical body; 
 a second end assembly, coupled to a second end of the tubular, further comprising a third cylindrical body having a plurality of recessed, axially oriented cylindrical half grooves located radially outward; 
 a fourth cylindrical body having a plurality of evenly spaced, recessed, axially oriented cylindrical half grooves located radially inward, wherein the third cylindrical body is disposed within, and axially aligned with, the fourth cylindrical body with the grooves of both cylindrical bodies align with, and complement each other to form a second plurality of cylindrical cavities within the assembly; 
 a sphere located within each of the second plurality of cylindrical cavities, forming a plurality of spheres, where the sphere can move during axial torque of the third cylindrical body relative to the fourth cylindrical body, and transmits a movement about the axis resulting from rotational movement of the third cylindrical body relative to the fourth cylindrical body; 
 a first plate axial aligned with and fixed to the second end assembly; and 
 a second plate axially aligned with and rotatingly coupled to the second end assembly, wherein the second plate can rotate independently of the first plate. 
 
     
     
       2. The apparatus of  claim 1  wherein the first plate is star shaped. 
     
     
       3. The apparatus of  claim 1  wherein the second plate is star shaped. 
     
     
       4. The apparatus of  claim 1  wherein the second plate is coupled to a test specimen. 
     
     
       5. The apparatus of  claim 4  further comprising a means for applying a torque about the common axis between the first plate and the second plate. 
     
     
       6. The apparatus of  claim 5 , wherein the means for applying a torque is a plurality of hydraulic actuators, each with a first end coupled to the first plate and a second end coupled to the second plate. 
     
     
       7. The apparatus of  claim 6 , wherein the means for applying a torque includes a plurality of bolts, each with a first end coupled to the first plate and a second end coupled to the second plate. 
     
     
       8. The apparatus of  claim 6 , wherein each hydraulic actuator is equipped with a pressure sensor to monitor and adjust the force output during the test procedure. 
     
     
       9. The apparatus of  claim 5 , wherein the means for applying a torque includes a control system capable of dynamically adjusting the torque applied based on real-time sensor feedback from the test specimen. 
     
     
       10. The apparatus of  claim 1 , wherein the apparatus can apply a predetermined torque to a test specimen. 
     
     
       11. The apparatus of  claim 1 , wherein the apparatus rotates a specimen while applying a predetermined torque to the specimen. 
     
     
       12. The apparatus of  claim 1 , wherein the test specimen is a tubular. 
     
     
       13. The apparatus of  claim 1 , wherein the rotational-coupling between the first plate and the second plate includes a bearing mechanism to facilitate smooth and consistent rotational movement.